Air preheater for locomotives



Dec. 24, 1929. TRGM ET AL AIR PREHEATER FOR LOCOMOTIVES 4 Sheets-Sheet Original Filed Sept. 5, 1923 Inv 812727216 1"! I.

0E1" ili $6 011,

7 9 mm 4P 1939- F. LJUNGSTROM ET AL 1,740,696

AIR PREHEATER FOR LOCOMOTIVES Original Fil ept. 5 1923 4 Sheets-Sheet 2 d .3 41

Dec. 24, 1929.,

F. LJUNGSTROM ET AL AIR PREHEATER FOR LOCOMOTIVES Original Filed Sept. 5. 1925 4 Sheets-Sheet 4 Ira/7161171701 3 11, 67161 -Brobe g 1'1. 0 .E'rilisson WM int-2 w.

Patented Dec. 24, 1929 UNITED STATES PATENT OFFICE FREDRIK LJUNGSTBOM, OF LIDINGO-BREVIK, ISIDOR BROBERG, OF SKARSATRA, LIDINGON, AND ERIK OTTO ERIKSSON, OLE LIDINGO-BREVIK, SWEDEN, ASSIGNORS T AKTIEBOLAGET LJ'UNGSTROMS ANGTURBIN, OF STOCKHOLM, SWEDEN, A COR- PORATION AIR PREHEATER FOR LOCOMOTIVES Application filed September 5, 1923, Serial No. 661,120, and in Sweden August 8, 1922. Renewed May 1c, 1928.

In boilers, especially those for stationary use, it has reviously been proposed to utilize the heat 0 the Waste gases escaping from the furnace, for the purpose of preheating the air flowing to the furnace. To this end, several constructions have been provided, but regenerative preheating has proved to give the highest efficiency. It has been suggested to arrange these regenerative air-preheaters in a rotatable manner, the same consisting of a rotor rotating partly in the waste gases of the boiler, and partly in the air to be preheated. Such regenerative preheaters have also been proposed for marine boilers and similar plants.

For locomtives, too, air-preheater plants have been proposed, in which the waste gases and the air pass on either side of partitions, accordin to the counter-current principle, the heat ein transmitted through the said partitions. or locomotives, however, a device of regenerative type has been previously suggested, but the object of thls device was to eflect a subsequent combustion of the waste gases in the regenerative apparatus, the heated air escaping from the regenerator passing, while burning, through certain tubes of the boiler back to the furnace. Under these conditions the regenerator would work at a very high temperature, and therefore it could not withstand the stresses imposed upon it for any length of time. Nor could fans be arranged for driving forth the waste gases or the air owing to the excessive temperature The present invention relates to an airpreheater for locomotives, and consists substantially in that the air-preheater is provided with a rotor'adapted to rotate partly in a channel, through which the waste gases from the boiler of the locomotive are passing, and partly in one or more channels for the air to be preheated, such channel or channels extending to the furnace on the outside of the boiler.

Preferably, the waste gases from the boiler are then driven forth by a fan to the smoke stack, the channel extending to the furnace being preferably arranged underneath the boiler.

Several embodiments of the invention are illustrated in the accompanying drawing. Fig. l is a partial elevation, shown partly in section, of a locomotive constructed according to the present invention. Fig. 2 shows another embodiment of the locomotive in elevation. Fig. 2 is a continuation of Fig. 2. F ig. 3 is an elevation of a further embodiment. Fig. 3 is a continuation of Fig. 3, and Fig. 4 a front view of Fig. 3. Figs. 5 and 6 are sections through the front portion of the smoke box of a locomotive devised in accordance with the invention.

In Fig. l, 1 designates the boiler, 52 the drivers cab, 13 the smoke box and 3 the smoke stack. In the embodiment shown, the waste gases passing from the furnace 11 through the tubes 12 enter the smoke box 13 into a baflied compartment, whence they pass through the rotor 14 and are driven out in the atmosphere by means of a fan 4 disposed in the smoke stack. The air to be preheated enters the channel 10 in the direction of the arrow a on account of the draft, in the furnace which, if desired, is effected by means of the fan 4, and on account of the speed of the train, the air then passing through the lower portion 14 of the rotor into the channel 15 situated underneath the boiler 1. Through the channel '15, the air is conducted to the furnace 11, wholly or partly beneath the grate 17 in the ash pit 16. The rotor 14 which in known manner contains a regenerative mass is heated during its passage through the hot Waste gases which are cooled thereby, the rotor being again cooled in heating the air to be preheated. The rotor is driven from a separate motor 5. To facihtate catching of the air, the outer portion of the channel 15 is shaped like a funnel 7 hav ing a jalousie-device arranged therein in known manner so that the air pressure produced by the speed of the train may be reduced when the furnace 11 is being fed. In the closed position of the jalousie-device the air is admitted in known manner on the sides of the said device. In the drawing, the jalousies are standing open.

In Fig 2, another embodiment of the invention is shown, in which the regenerative rotor is indicated by the dotted lines 20. This rotor 20 is placed in front of the superheating device 21 of the locomotive, entirely within the smoke box 22 which is thus divided in two parts, i. e. a front part and a rear part. The front part as well as the rear part of the smoke box are also divided in two portions by means of the partitions 23 and 24 respec tively, in such a manner that the waste gases will pass in the direction of the arrow 1) through the smoke box and the upper portions of the rotor, the waste gases being then driven out into the smoke stack by the fan device 26. The air to be preheated enters in the direction of the arrow 0 and passes through the lower portions of the smoke box and the rotor into a channel 28 situated underneath the boiler of the locomotive, through which channel the heated air is conducted under the furnace 29 of the locomotive. The upper front portion of the smoke box of the locomotive is connected with a cinder collector 30, whereby cinder or soot forming may be removed from the smoke box also in the run of the engine. The smoke box may also be arranged in such a manner as to permit of being opened by means of hinges or the like provided in the flanges 31, for the purpose of facilitating inspection during stops at stations or in locomotive sheds. In this open position the superheater and the tubes of the boiler will also be accessible for sweeping and inspection. The channel 28 conducting the air under the grate in the furnace 29 is in this embodiment situated on a level with the frame 32 of the locomotive, but of course this channel may be conceived as arranged in some other place provided the same is disposed outside the boiler and'conducts the air substantially under the grate of the boiler.

In the embodiment of the invention disclosed in Figs. 3 and 4, the rotating regenerator is disposed in the front portion-of the smoke box, before the smoke stack of the locomotive. In these figures, 41 denotes the regenerative rotor. The waste gases pass through the top portion of the smoke box over the partitions 42 and 43, from which part they are driven out through the smoke stack 45 in the direction of the arrow cl by means of the fan device 44. The air to be preheated enters under the partition 42 in the direction of the arrow 6 and passes, while being heated, through the bottom portion of the rot-or 41, and then through the channel 47 into the channel 48 situated on a level with the frame, through which last-mentioned channel the air is conducted to the furnace 49. In the embodiment shown, a cinder collector 50 is provided to collect soot and the like. The rear part of the smoke box is accessible through the manhole 51. For sweeping and inspection of the tubes and the superheater etc. of the boiler, the front portion of the smoke box may be opened by means of hinges provided in the flange 52, whereby the regenerative rotor may be swung outwards so as to render the tubes accessible. The portion of the smoke stack 45 situated underneath the flange 53 will also take part in this outward movement of the front portion of the smoke box. In feeding the fire of the boiler, where the draft cannot be effected by means of the fan, the waste gases are admitted through the opening 54 direct into the smoke stack, without being caused to pass through the air-preheater. When the pre-heater is used, the said opening 54 may be closed by means of a damper 54. Preferably, the preheater is also employed in starting the fire, as soon as a pressure has been obtained in the boiler which is high enough to permit of starting the fan device 44. This fan device 44 may also be driven in some other way, for instance electrically, in which case firing may take place with the use of preheating, independently of the prevailing steam pressure. It will be seen from Fig. 4 that the rotor occupies the'cross section of the smoke box completely in such a manner that the outer diameter of the rotor nearly coincides with the inner diameter ofthe smoke box. To effect a control of the air forced in through the speed of the train, the forwardly directed opening of the air channel is in known manner provided with jalousies 80, which may be closed, for instance during firing, the air required to maintain the fire in the furnace being taken in through small holes or openings 55 in the shell of the smoke box.

In the embodiments above described, the driving machinery of the locomotive has not been shown, the invention being inde endent of the design of said machinery. igs. 5 and 6 show sections through the front portion of a smoke box having a regenerative air-preheater mounted therein. Above all, these figures show embodiments in which the fan and the rotor are driven from the same driving motor, for example from the same turbine. In these fi res, the chain-dotted line indicates the ront wall of the boiler through which the tubes of the boiler are extended, said tubes opening in the upper rear portion of the smoke box limited by the partition 61. The waste gases pass in the direc tion of the arrow f, as previously described, about the smoke stack and through the upper ortion of the annular rotor 67 to the upper ront portion 63 of the smoke box, whence the gases are driven out by means of the fan 64 disposed in the hollow of the annular rotor, through the smoke stack 65 shaped as a diffuser and extending into the hollow of the rotor. The air to be preheated enters at 6, passes in the direction of the arrow g through the bottom portion of the rotor 67, and is then conducted'through the channel 68 to the furnace.

In the embodiment shown in Fig.5, the fan 64 is in known manner built together with a turbine 69, the frame of which at the same time constitutes an oil reservoir for the lubrication of the aggregate. Through a toothed gearing 71 on the other end of the turbine shaft, which gearing may be built'together with the gearing of a toothed wheel pump efiecting the lubrication, the motion of the turbine is transmitted, while being subjected to a reduction in speed, onto a shaft 72, from which the motion is transmitted onto a shaft 74 by means of a chain 73, a belt or the like. The chain 73 or the belt respectively may be enclosed, either entirely together with the pertaining sprocket wheel or pulley respectively, or in such a manner that the two sides of the chain or the belt respectively are each per se surrounded by casings. Attached on the shaft 74 is a roller 75 running on the outside of the shell of the rotor, or on a band 76 arranged thereon. The fan 64 and the rotor 67 are thus driven from the same drivin motor, i. e. the turbine 69.

In the enfiodiment shown in Fig. 6, the turbine 69 is also mounted on an oil reservoir 70. The shaft end of the turbine turned away from the fan 64 is connectedwith an oil pump 77 pumping oil not only for the lubrication of the turbine aggregate, but also through the piping 78 to a gear wheel pump 79 serving as a motor. The shaft of this gear wheel pump, which is driven by oil forced through the salne, carries the roller 75 on its one end, said roller running on the outer shell of the rotor or on a band 76 mounted thereon, as described hereinbefore. In this case, too, the turbine 69 is thus driving both the fan 64 and the rotor 67.

In addition to being guided by the roller 75 driving the rotor, the latter is guided and carried in known manner by two or more other rollers which, if desired, may be formed as driving rollers. The expansions occurring through the heating of the rotor effect an increase in the diameter of the rotor, on account of which the roller 75, for example, must be pressed in a yielding way, by means of springs or other means, against the shell of the rotor or against the band 76. This resiliency or adaptability for example of the roller 75, may be brought about by arranging the whole pump 79 or the corresponding device so as to be movable on the shell of the smoke box, or by arranging the roller 75 movable on its shaft.

Further embodiments may be conceived without exceeding the scope of the invention, and all of the arrangements which have heretofore been proposed for regenerators pertaining to boilers of other types may, as far as they are found suitable for the purpose, also be provided in the regenerator arrangement for locomotives hereinbefore described.

lVhat we claim as new and desire to secure by Letters Patent of the United States of America is 1. Anair preheating device for locomotives comprising a frame supporting metal platesacting as regenerating material, said frame being rotatably mounted in the smoke box of the locomotive boiler in a plane forming substantially a right angle with the longitudinal direction of the boiler, said smoke box being divided into two separate chambers through which the rotating frame moves on its rotation, the one of said chambers communicating on the one hand with thefurnace of the locomotive boiler and on the other hand with the uptake of the locomotive, whereas the other chamber communicates on the one hand with the atmosphere and on the other hand with the space below the grate of the furnace by means of a channel extending below the boiler, a fan being provided ada ted to exhaust the waste gases from the smo e box into the uptake, said fan being placed in a central bore provided in the rotating frame.

2. An air preheating device for locomotives comprising a frame supporting metal plates acting as regenerating material, said frame being rotatably mounted in the smoke box of the locomotive boiler in a plane forming substantially a right angle with the longitudinal direction of the boiler, said smoke box being divided into two separate chambers through which the rotating frame moves on its rotation, the one of said chambers communicating on the one hand with the furnace of the locomotive boiler and on the other hand with the uptake of the locomotive, whereas the other chamber communicates on the one hand with the atmosphere and on the other hand with the space below the grate of the furnace by means of a channel extending below the boiler, a fan being provided adapted to exhaust the waste gases from the smoke box into the uptake, said fan together with its driving means being placed in a central bore provided in the rotating frame, the uptake eing lengthened at the bottom so as to extend into said bore of the frame.

3. An air preheating device for locomotlVQS comprising a frame supporting metal plates acting as regenerating material, said frame being rotatably mounted in the smoke box of the locomotive boiler in a plane forming substantially a right angle with the longitudinal direction of the boiler, said smoke box being divided into two separate chambers through which the rotating frame moves on its rotation, the one of said chambers communicating on the one hand with the furnace of the locomotive boiler and on the other hand with the uptake of the locomotive, whereas the other chamber communicates on the one hand with the atmosphere and on the other hand with the space below the grate of the furnace by means of a channel extending below the boiler, a fan being provided adapted to exhaust the waste gases from the smoke box int-o the uptake. the axis of rotation of the the fan.

4. In a locomotive, a boiler, a smoke box, a smoke stack, a preheater of the regenerative type in said smoke box having passages therethrough, means for successively passing flue gases through said passages to said smoke stack for heating the regenerative material 111 said passages, and for passing combustion air through said passages to be heated, and a bypass t'or passing flue gases directly to said smoke stack.

5. In a locomotive, a boiler, a smoke box, a smoke stack, a preheater of the regenerative t pe in said smoke box having passages theretlirough. means for continuously rotating said preheater, means for successively passing flue gases through said passages to said smoke stack for heating the regenerative material in said passages, and for passing combustion air through said passages to be heated, and a by-pass for passing flue gases direct- 1y to said smoke stack.

6, In a locomotive, a boiler, a smoke box. a smoke stack, a preheater of the regenerative type in said smoke box having passages therethrough, means for successively passing flue gases through said passages to said smoke stack for heating the regenerative material in said passages, and for passing combustion air through said passages to be heated, and a valve-controlled by-pass for passingflue gases directlyto said smoke stack.

7. In a locomotive, a boiler. a smoke box, a smoke stack, a preheater of the regenerative type in said smoke box having passages theret rough, means for continuously rotating said preheater, means for successively passing flue gases through said passages to said smoke stack for heating the regenerative material in said passages, and for passing combustion air through said passages to be heated, and a valve-controlled by-pass for passing flue gases directly to said smoke stack.

8. In a locomotive, a boiler, a smoke box, a smoke stack, a preheater of the regenerative tvpe insaid smoke box. said preheater having the form of an annulus having a central opening, separated passages in said preheater each containing regenerative material, means for passing flue gases successively through said passages and through said central opening to said smoke stack, and means for passing a combustion air through said passages to be heated therein.

9. In a locomotive, a boiler, a smoke box, a smoke stack, a preheater of the regenerative type in said smoke box, said preheater having the form of an annulus having a central opening, separated passages in said preheater each containing regenerative material, means for continuously rotating said preheater, means for passing flue gases successively through said passages and through said central opening to said smoke stack, and means for passing combustion air through said passages to be heated therein.

10. In a locomotive, a boiler, a smoke box, a smoke stack, a preheater of the regenerative type in said smoke box, said preheater having the form of an annulus having a central opening, separated passages in said preheater each containing regenerative material, means for passing flue gases successively through said passages and through said central opening to said smoke stack, means for passing combustion air through said passages to be heated therein, a fan in said opening, and means for rotating said fan and said 'preheater.

11. In a locomotive, a boiler, a smoke box, a preheater of the regenerative type having passages therethrough in said smoke box, and means for conducting flue gases to be cooled and combustion air to be heated successively through said passages, said flue gases and air flowing through said preheater in substantially parallel paths, part of said flue gas flow being in the same direction as said air flow.

12. In combination, a boiler, a flue gas outlet, a preheater of the regenerative type in said outlet, said per-heater having the form of an annulus having a central opening, separated passages in said preheater each containing regenerative material, means for conducting flue gases to be cooled successively through said passages and through said central opening, and means for conducting combustion air through said passages to be heated therein.

13. In a locomotive, a boiler, a smoke box in advance of said boiler, a combustion chamber in rear of said boiler, means providing separate flue gas and combustion air passage- Xvays in said smoke box, a preheater of the regenerative type in said smoke box having passages therethrough, means for communicating said preheater passages successively with said gas and said air passageways, and means for conducting the heated air to the combustion chamber.

14. In a locomotive, a boiler, a smoke box in advance of said boiler, a combustion chamber in rear of said boiler, means providing longitudinally disposed separate flue gas and combustion air passageways in said smoke box, a preheater of the regenerative type in said smoke box, having passages therethrough, means for communicating said preheater passages successively with said gas and air passageways, and means for conduct ing the heated air to the combustion chamber.

15. In a locomotive, a boiler, a smoke box in advance of said boiler, a combustion chamber in rear of said boiler, means providing separate flue gas and combustion air passageways in said smoke box, a preheater of the regenerative type in said smoke box having passages therethrough, means for rotating said preheater to successively communicate said preheater passages with said gas and air passa sways, and means for conducting the heate air to the combustion chamber. 16. In a locomotive, a boiler, a smoke box in advance of said boiler, a combustion chamber in rear of said boiler, means providin longitudinally disposed separate fluegas an combustion air passageways in said smoke passages therethrough, means for commumcatingsaid preheater passages succewvely with said gas and air pwa s and means for conducting the heated air be 0% the boiler grate.

18. In a locomotive, a boiler, a smoke box in advance of said boiler, a combustion chamher in rear of said boiler, means. providing separate flue gas and combustion air passageways in'said smoke box, a preheater of the re- Y generative type in said smoke box, having passages therethrough, means for rotating said preheater to successively communicate said preheater passages with said and air Eassa 'Iways, and meansfor con noting the eat air below the boiler grate.

t In testimony whereof we afiix our. signa- FREDRIK LJUNGSTROM.

ISIDOR BROBERG.

ERIK 'OTTO ERIKSSON. 

